According to rumors that I read, Chelsea has agreed to exchange 2 star players and a certain amount of money to recruit Oshimen. It is known that the price tag for Napoli is quite high and Chelsea is negotiating by donating 2 of their players and the players that Chelsea sacrificed are Casadei and Lukaku.
I think this is a quite profitable exchange for Napoli because it gets 2 players at once and a transfer fee, at least Antonio Conte has several options to use that players.
Chelsea consideration would not be only the price of Victor Osimhen but his wages meaning they would not continue going after him regardless of if Napoli agreed to their swap deal. The money would not have been a problem for Chelsea to sign Victor Osimhen if he was not on a high salary. Chelsea has Jackson which although many people are considering him a flop but he has a good statistics if you look at other strikers that has played for Chelsea before him in their first season. If he is being taught well, He can become a top striker for Chelsea because his problem is not the lack of opportunity to score but his conversation rates. He needs to be taught how to take this chances and what to do when in front of the goalkeeper. Instead of Chelsea throwing away money in the transfer window, they should build on what they have already.
Victor Oshimen is a star player so it is only natural that his salary is high. If Chelsea wants to bring in Oshimen they also have to be prepared for bigger expenses and maybe Oshimen will have the highest salary among other Chelsea players.
Yes, actually Chelsea already have good players in their squad such as Cole Palmer and Jackson, they both performed impressively last season.
But do you know what Chelsea is like? they feel dissatisfied if they haven't bought a player yet, while Oshimen is the player Chelsea is most interested in, even though bringing in Oshimen may not necessarily achieve success.